Before you spend, a CB350/4 rear axle works as a puller for the CB500/4 Rotor. Use the wheel spacers as the slide hammer. The Puller for the 350/4 I used was an M18x1.5 bolt., or if you haven't got the CB350/4 Axle, an M16x1.5 bolt is cheaper than the Honda tool!
Regards,
Nigel.